1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
A hollow golf club head has been known. The hollow structure increases a head volume and a moment of inertia. A so-called wood type golf club head is usually hollow. The volume of a hollow part is increased and the thickness of the head is thinned with the increase in size of the head. When the hollow part is great, a hitting sound is loud. Since the vibration of the head is great when the thickness is thin, the hitting sound is loud. The head increased in size causes a loud hitting sound.
A golf club head for obtaining a good hitting sound is disclosed. The invention considering the hitting sound is proposed. Japanese Patent Application Laid-Open No. 2006-204604 (US2006/0172818 A1) discloses a curved rib extending to a heel side edge part from a toe side edge part of a sole. Japanese Patent Application Laid-Open No. 2003-102877 discloses a rib provided on an abdominal part of an out-of-plane secondary bending vibration in a sole part.